EURURO Vol. 71 No. 4

E121 692

Letter to the Editor
Re: Daniel E. Spratt, Hebert A. Vargas, Zachary S.
Zumsteg, et al. Patterns of Lymph Node Failure after
Dose-escalated Radiotherapy: Implications for Extended
Pelvic Lymph Node Coverage. Eur Urol 2017;71:37–43
A Step Forward in the Era of Functional Imaging?
We read with interest the article by Spratt and colleagues
recently published in European Urology. The authors
analyzed patterns of abdominopelvic lymph node (LN)
failure via radiographic LN mapping in a large series of
prostate cancer (PC) patients treated with definitive dose-
escalated radiation therapy (RT) without pelvic LN RT.
In their experience, radiographic failures were most
frequently found above the L5/S1 landmark. Thus, for
selected PC patients, the current pelvic LN RT recommen-
dation could be revisited. The authors state that androgen
deprivation therapy could prevent or minimize marginal
and/or out-of-field recurrences. Moreover, Spratt et al
recommended revisiting of the current RT field recommen-
dation for pelvic LNs (up to the superior border of the
internal/external iliac vessels) because of inadequate RT
coverage.
Looking at their findings a type of pelvic RT volume
customization could be introduced in clinical practice. In
fact, in the analysis by Spratt et al , PC patients with
Gleason score 8 were at particular risk of dissemination to
distant nodes. However, this PC category deserves accurate
pre-RT staging to exclude distant dissemination . Recent
data support the value of molecular imaging in the
therapeutic approach to high-risk PC. The reliability of
new tracers (such as 11C- and 18F-choline and/or 68Ga-
labeled prostate-specific membrane antigen [PSMA]) for PC
has been investigated in several series While choline
positron emission tomography (PET) is not indicated for
routine local tumor staging, it seems to have better
performance than conventional morphological imaging in
LN staging and for all PC patients with suspected distant
metastases. In addition, 68Ga-PSMA seems to be more
sensitive and specific than choline . All these molecular
imaging advances should be introduced to pre-RT target
assessment procedures to modify the treatment strategy in
terms of: (1) changes in treatment intent from radical to
palliative; (2) changes in RT volumes and doses; and (3)
integration with other therapies . Unfortunately, Spratt
et al only included PC patients with complete abdominal
and pelvic imaging with magnetic resonance imaging,
computed tomography (CT), and/or fluorodeoxyglucose
PET/CT to determine the pattern of nodal relapses, and
more specific and sensitive staging tools (eg, choline PET
and/or PSMA PET) were not used. Undoubtedly, this
methodology could affect the real value of the results,
and probably resulted in underestimation of the real PC
staging.
An ongoing trial, RTOG 0924, as mentioned by the
authors , will evaluate the impact of extended pelvic RT
in selected PC patients. From our point of view, in the
absence of accurate pre-RT staging with functional imaging,
the issue of pelvic node RT will remain controversial.
Conflicts of interest: The authors have nothing to disclose.
References
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ava ilable at
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DOI of original article: .
0302-2838/# 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.